I received my Ph.D. from Duke University in 2001, where I worked under the guidance of Jim Clark.  While at Duke, my field work took me to the Coweeta Hydrologic Laboratory in western North Carolina (an LTER site), where I studied seed dispersal, seed banking and density-dependent mortality for co-occurring temperate tree species.  I then spent three years as a postdoc at the University of Minnesota, working with David Tilman at the Cedar Creek Natural History Area (another LTER site).  There, I worked on the diversity-productivity relationship, the effects of global change on seed production, and the implications of recruitment limitation for mid-Western prairies.  In a subsequent postdoc at University of California, Santa Barbara (working with Jonathan Levine), I focused on the factors that allowed Mediterranean annual grasses to dominate over the diverse California annual grasses and forbs.  I arrived at University of Washington in 2006.

Can the invasion of non-natives affect pollinator services? Historically dominated by forbs and bunchgrasses, Puget Trough prairies are now undergoing extensive invasion by sod-forming grasses. Where they are locally abundant, these exotic grasses alter the spatial distribution of native forbs, whose flowers offer pollen and nectar resources to prairie pollinators. Simultaneously, they alter community structure by replacing patchy bunchgrass tufts with dense stands of exotic grass, important because the bare ground between tufts offers habitat for ground-nesting bees. 

 My current project uses historical flowering data from prairie herbarium specimens, in combination with contemporary plant abundance data, to identify potential seasonal gaps in pollinator resources in prairies with a range of exotic grass densities.  I plan to complement this with field data on pollinator limitation of prairie forbs in more- and less-invaded sites and on relative contributions of native and exotic floral resources to key pollinators. 

How does native eelgrass (Zostera marina L.) affect its own spatial distribution?  Organisms modify their biotic and abiotic environments. If large enough, these modifications may feed back to regulate the organisms’ own population and community dynamics. Native eelgrass (Z. marina) is a common marine angiosperm which grows in patches or continuous meadows in estuaries. It spreads by clonal branching or by seed. Previous studies have suggested that eelgrass facilitates its own spread by ameliorating local water motion (waves and currents). Currently, I am manipulating eelgrass stem density and gap size to measure flow, sediment erosion, susceptibility to removal disturbance in winter storms, and changes in eelgrass morphology and demography. With these and future data, I hope to develop a spatially-explicit model of eelgrass population dynamics with and without environmental modification by eelgrass itself. Understanding natural mechanisms of population maintenance or demise is useful for eelgrass conservation. Eelgrass acts as important habitat for many animals, it protects shorelines from erosion, and it is unfortunately declining worldwide.